It is known in the automotive vehicle industry to provide cargo storage and restraint compartments formed by attaching sections of netting to surfaces within the passenger and/or cargo areas of a vehicle. The netting is generally formed from elastic cords, non-elastic cords, or a combination thereof to create a compartment that is somewhat expandable if desired. For example, it is common to attach a non-elastic netting section to the left and right hand side walls of a vehicle's trunk or rear cargo area so that the net stretches across the area a short distance forward of the rear bumper. Objects such as grocery bags can then be placed behind the net barrier and are prevented from sliding or rolling forward when the vehicle is in motion.
It is known to secure a storage net to a vehicle at one or more points by forming loops in the net cord or an associated bungee cord and placing the loops over anchor which is fixed to the vehicle at the appropriate location. Such an anchor typically projects approximately 15 to 20 millimeters above the surface of the vehicle interior and has a mushroom-shaped or T-shaped head around which the loop or cord is passed.
It is known for tie-down anchors to be secured in the desired position on a surface of the vehicle by engaging a threaded bolt or stud which projects from the surface. Such studs are typically on the order of 4 to 8 millimeters in diameter. One type of known anchor has a threaded hole or a captive nut on its lower surface so that it may be threaded into engagement with the stud. This has the drawback of requiring that the anchor be rotated either by hand or by a power tool to thread it onto the stud. Threading the anchor onto the stud by hand is time consuming and labor intensive. The use of a power tool adds costs for both procurement and maintenance of the tool.
It has therefore been found advantageous to use a tie-down anchor that may be pushed straight onto the stud and which engages the threads without requiring that the anchor be rotated. This has been achieved by barbs which project radially inward into a hole in the bottom the anchor to engage the threads of the stud when the stud is inserted therein. The barbs are angled toward the top of the anchor and are flexible so that they deflect outwardly as the stud is inserted into the hole and spring back so that the tips of the barbs engage the threads in a ratcheting effect and prevent the stud from being withdrawn from the hole. The anchor may be removed only by twisting it to unthread it from the stud, in the manner of a conventional threaded nut.
One known push-on anchor, depicted in FIG. 1, comprises a mushroom portion 100 having upper and lower radial flanges 102,104 for retaining a loop 106 when it is passed therearound, and a separately formed thread engagement tube 108 having barbs 110 of the type described hereinabove disposed radially about its interior. The mushroom 100 and the thread engagement tube 108 are snapped into engagement with one another, a cylinder 112 formed on the bottom of the mushroom fitting downwardly into the upper end of the thread engagement tube, and detent prongs 114 projecting outwardly through windows 116 in the tube to hold the two portions together. The mushroom has a blind, unthreaded hole 118 extending upwardly into it from the lower surface of the cylinder for receiving the top end of the stud when the anchor is mounted thereon.
The two portions of the prior art push-on anchor must be molded separately because to form it as a single piece would require that the barbs be molded on the interior of the blind hole extending into the anchor. This is impractical when using conventional injection molding technology, unless removable cores or some other cost-adding technology is applied. The molding of the anchor as two separate pieces and subsequent assembly of the pieces adds significantly to the price of manufacturing the prior art push-on anchor. It would therefore be desirable to produce a push-on anchor as a single, integrally molded unit in order to reduce manufacturing costs.